The present invention relates to an electrosurgical device for coagulating and for making incisions in or severing tissue such as for instance blood vessels, said device comprising at least one immobilizing means for immobilizing a tissue portion to be coagulated and incised and first electrical means for applying a first electric power to the tissue portion immobilized by the immobilizing means for coagulating at least part of said tissue portion.
An electrosurgical device of this type is disclosed in U.S. pat. No. 5,445,638 to Rydell et al. In this known device two moveable forceps jaws are provided for clamping the tissue portion therebetween, the forceps jaws being provided with electrical means to provide electric power for coagulating the tissue portion clamped therebetween. A cutting instrument with one or more cutting edges is provided for being moved between the forceps jaws for mechanically cutting the tissue portion after coagulation thereof has taken place.
When tissue such as for instance a blood vessel has been coagulated, the tissue often becomes relatively tough requiring a relatively large force to be exerted on the cutting instrument to perform the required incision. Furthermore each incision dulls the cutting edge thereby requiring even larger force for each incision. In many cases, the cutting edge has been dulled so much after one or two incisions that the device must be replaced if, as is often the case, several incision are to be performed during the same operation. As the device normally is intended to be discarded after use, this is expensive, and furthermore it is not desirable to have to re-move and introduce such devices during such surgery.
When tissue such as for instance a blood vessel or other tissue is coagulated through the supply of electric power to the blood vessel or other tissue, a risk exists of generating excessive carbonization or charting of the tissue through the supply of electric power to the tissue and further a disadvantage of generating smoke through the heating of the tissue in question through the evaporation of water and/or through possible carbonization or charring of the tissue through the supply of power to the tissue. It is to be understood that the generation of any excessive carbonization or charring of the tissue of a patient in itself constitutes a risk to the individuals"" health and may cause serious injuries and possibly also give origin to cancer diseases It is also to be understood that the generation of smoke may on the one hand slow down the overall operation and prolongate the operation, which also may cause a risk to the patients"" health, and on the other hand increasse the risk of the surgeon using the electrosurgical device incorrectly and thereby causing harm or injury to the patient.
Additionally, because of the toughness of the tissue and the manual application of the cutting force, the manipulation of the device is less smooth and easy than desirable, and the cutting operation may give rise to a snap-like reaction which is undesirable in this type of surgery.
A main object of the invention is thus to provide an electrosurgical device of the type in reference by means of which multiple incisions may be performed with the same device and without the disadvantages of the known device described above.
A further object of the invention is to provide an electrosurgical device of the type in reference by means of which the risk of generation of smoke through evaporation of water and/or carbonization or charring of the tissue through the supply of electric power to the tissue is to a great extent reduced or eliminated.
According to the invention, this object is achieved by providing the device with at least one electric power application means for applying a second electric power to at least part of said tissue portion for making incisions in said tissue portion, and by providing the device with at least one tubular element for supplying an electrically non-conductive, cooling liquid to the tissue portion, to which electric power is applied for making the incisions.
The invention, to be more precise, relates to an electrosurgical device for coagulation and for making incisions in or severing tissue such as for instance blood vessels, said device comprising:
at least one immobilizing means for immobilizing a tissue portion to be coagulated and incised,
first electrical means for applying a first electric power to the tissue portion immobilized by the immobilizing means for coagulating at least part of said tissue portion,
at least one electric power application means for applying a second electric power to at least part of said tissue portion for making incisions in said tissue portion and
at least one tubular element for supplying an electrically non-conductive, cooling liquid to said tissue portion.
Hereby, the second electric power applied gives rise to a thermal influence on the tissue portion whereby the incision is performed by the effects of the thermal influence which is not subject to alteration from incision to incision and therefore gives uniform handling characteristics as well as a smooth and easy operation because the toughness of the tissue has very reduced or no effect on the force to be exerted for performing the incision. By thermal Influence is meant herein the diverse effects of electric power applied to tissue and which are well known to those skilled in the art. Through the supply of the electrically non-conductive, cooling liquid to the tissue portion to which electric power is applied, the tissue is cooled and in particular any surface charring is to a great extent reduced or eliminated preventing the generation of smoke through charring and evaporation of water from the tissue.
Although, for some uses, it may be advantageous to combine a mechanical cutting effect with the thermal cutting effect for instance by providing the electric power application means according to the invention with a mechanical cutting edge, in the currently preferred device according to the invention, the electric power application means are configured such, for instance being blunt, that the incision or severing is substantially exclusively achieved by means of said second electric power.
Hereby it is achieved that the cutting characteristics of the device are not influenced at all by any dulling of a cutting edge. Furthermore, this feature is advantageous in that the risk of cutting through tissue that has not ben adequately coagulated for eliminating bleeding is greatly reduced or eliminated because the thermal effect of the second electric power applied by the electric power application means will tend to coagulate any tissue that has not been sufficiently coagulated by the application of the first electric power.
In the known device described above, the severing of a blood vessel, for instance, where the coagulation has not been performed correctly or in-sufficiently will give rise to bleeding when the blood vessel is severed by the cutting edge while the device according to the invention will tend to coagulate any insufficiently coagulated tissue or blood while performing the severing operation. This affords a device with a greatly increased safety margin whereby complications during surgery are reduced both in number and severity.
According to the invention and depending on the characteristics of the surgery to be performed, the first and/or the second electrical power may be constituted by an electric current signal, an electric voltage signal or a combination thereof, and the signal may be a DC or AC signal such as a LF, an HF or an RF signal for instance a VHF, a UHF or a microwave signal.
In the currently preferred embodiment of the device according to the invention, the first and second electric powers are obtained by means of substantially identical electric current or voltage signals. Hereby a common, relatively inexpensive signal generating means may be employed for generating the required signals. However, for some applications it may be advantageous that the respective electric current or voltage signals be different so as to obtain, for instance, a relatively higher incision power than coagulating power.
Although many different types of grasping means, pinning means and the like may be utilized as tissue immobilizing means, in the currently preferred embodiment of the device according to the invention, the immobilizing means comprise first and second moveable forceps jaws and moving means for opening and closing the first and second jaws relative to one another for holding and/or clamping the tissue portion therebetween.
When severing blood vessels it is important that the vessel be compressed to the correct degree to achieve the desired coagulation. Therefore, in the currently preferred embodiment of the device according to the invention, the moving means comprise adjustable spring loading means for applying a specific or an adjustable spring load for closing the first and second jaws relative to one another, and the spring load may be manually adjustable depending on the characteristics of the tissue portion to be held between said jaws. Hereby, the clamping effect may be adjusted according to the diameter, type and degree of calcification of the blood vessel to be severed. The surgeon may thus adjust the spring load and thereby the clamping effect prior to performing the severing of the blood vessel and thus avoid the inconvenience and complication of the known device described above where the surgeon must maintain the pressure manually during almost the whole severing operation.
In the currently preferred embodiment of the device according to the invention, the device furthermore comprises electrical switching means for applying the first and second electric powers independently of one another and preferably sequentially.
The currently preferred embodiment of the device according to the invention comprises:
an elongated tubular member having a proximal and a distal end and a lumen extending therethrough,
first and second moveable forceps jaws extending from said distal end, opening and closing means for opening and dosing the first and second forceps jaws relative to one another,
first electrical means for applying a first electric voltage across the first and second forceps jaws,
an electric power application means extending from said distal end and arranged for being moved through a tissue portion held between the first and second forceps jaws, and
second electrical means for applying a second electric voltage to the electric power application means relative to the first and/or the second forceps jaws.
Preferably, the first electric voltage is substantially equal to the second electric voltage.
The currently preferred embodiment of the device according to the invention further comprises a handle fixed to said proximal end of the tubular member, said handle advantageously comprising forceps activating means for manually activating the opening and closing means, spring load adjusting means for manually adjusting the spring load of the spring loading means, incision activating means for manually activating the movement of the electric power application means through the tissue portion, and switching means for activating the first and second electrical means for applying said first and second electric voltages.
So as to render the device according to the invention as practical as possible for the surgeon and avoid any risk of erroneous operation thereof, in the currently preferred embodiment of the device, the switching means are adapted to cooperate with the incision activating means such that the first electric voltage is applied in the deactivated condition of said incision activating means while the second electric voltage is applied in the activated condition of said incision activating means. Hereby the coagulating power is automatically succeeded by the incision power when the incision activating means are activated.
According to the currently preferred embodiment of the device according to the invention described above and including the tubular member and the handle, the said at least one tubular element is exposed at said distal end of said tubular member.
Further in the currently preferred embodiment of the device according to the invention, the said additional tubular element preferably includes a pump for controlling the supply of said electrically non-conductive, cooling liquid.
In the currently preferred embodiment of the device according to the invention the electric power application means comprise a plate member having a blunt leading edge, and the plate member except the leading edge portion is electrically insulated from the surroundings such that electric power only may be supplied to the tissue portion through said leading edge portion exclusively.
In an alternative embodiment of the device according to the invention, the electric power application means may advantageously comprise a wire member arranged for being moved through the tissue portion and for supplying electric power to the tissue portion.
The invention further relates to an electrosurgical device for coagulating and for making incisions in or severing tissue such as for instance blood vessels, said device comprising:
at least one immobilizing means for immobilizing a tissue portion to be coagulated and incised,
first electrical means for applying electric power to the tissue portion immobilized by the immobilizing means for coagulating at least part of said tissue portion,
at least one incision means for making incisions in at least part of said tissue portion,
the immobilizing means comprising adjustable spring loading means for applying an adjustable spring load for immobilizing the tissue portion, and at least one tubular element for supplying an electrically non-conductive, cooling liquid to said tissue portion.
Preferably, the spring load is manually adjustable depending on the characteristics of the tissue portion to be immobilized by the immobilizing means.
In the currently preferred embodiment of the device according to the invention, the immobilizing means comprise first and second moveable forceps jaws and moving means for opening and closing the first and second jaws relative to one another for holding the tissue portion there-between and the moving means comprise adjustable spring loading means for applying an adjustable spring load for closing the first and second jaws relative to one another.
The invention furthermore relates to a method of severing blood vessels, the method comprising the following steps:
applying a first electric power to a portion of the blood vessel adjacent the intended severing location for coagulating the blood and tissue in said region,
supplying an electrically nonconductive, cooling liquid to said portion of said blood vessel and/or to said region while applying said first and/or said second electric power, respectively, and
applying a second electric power to said region at said severing location for severing the blood vessel.
Preferably, said portion of the blood vessel is compressed prior to and/or during the application of the first electric power, the degree of compression being such the blood and tissue coagulates to form a permanent coagulation clot in the blood vessel adjacent said severing location for allowing severing of the blood vessel without bleeding.
Advantageously, the first and/or the second electrical power is constituted by an electric current signal, an electric voltage signal or a combination thereof, and the signal is a DC or AC signal such as a LF, an HF or an RF signal for instance a VHF, a UHF or a microwave signal.
In the currently preferred embodiment of the method according to the invention, the first and second electric powers are obtained by means of substantially identical electric current or voltage signals.
Although any suitable values of the electric powers and any suitable signal frequency may be utilized for various purposes, in the currently preferred embodiment of the method according to the invention, the first and/or second electric powers are delivered by a 60 waft 500 kHz generator.
Finally, the Invention furthermore relates to a method of coagulating and for making incisions in or severing tissue such as for instance blood vessels, the method comprising the following steps:
providing at least one immobilizing means for immobilizing a tissue portion to be coagulated and incised,
providing first electrical means for applying a first electric power to the tissue portion immobilized by the immobilizing means for coagulating at least part of said tissue portion,
providing at least one electric power application means for applying a second electric power to at least part of said tissue portion,
immobilizing said tissue portion by applying said immobilizing means to the tissue portion,
applying the electric power to the tissue portion for coagulating at least part of the tissue portion,
applying the second electric power to at least part of said tissue portion for at least assisting in performing an incision in or severing the tissue portion, and supplying an electrically non-conductive, cooling liquid to said tissue portion while
applying said first and/or said second electric power to said tissue portion.
Advantageously, the first and/or the second electrical power is constituted by an electric current signal, an electric voltage signal or a combination thereof, and the signal is a DC or AC signal such as a LF, an HF or an RF signal for instance a VHF, a UHF or a microwave signal.
In the currently preferred embodiment of the method according to the invention, the first and second electric powers are obtained by means of substantially identical electric current or voltage signals.
Although any suitable values of the electric powers and any suitable signal frequency may be utilized for various purposes, in the currently preferred embodiment of the method according to the Invention, particularly when being utilized for severing blood vessels, the first and/or second electric powers are delivered by a 60 Watt 500 kHz generator.
Although any suitable electrically nonconductive, cooling liquid may be used, experiments have revealed that the product Glycin (copyright) has proven to fulfil the purpose of on the one hand allowing a cooling of the tissue to which electric power is applied and on the other hand preventing electric discharging from the tissue through conduction of electric current through the cooling liquid which would have occurred provided the cooling liquid was electrically conductive.